1. Technical Field
The present invention relates to a robot hand, a robot, and a control method for the robot hand.
2. Related Art
A robot that grips an object to be gripped is utilized in work such as assembly work and classification work. A user desires to cause the robot to grip various objects to be gripped. JP-A-2011-73099 (Patent Literature 1) discloses a gripping device that can grip objects ranging from a very hard object to a soft object. According to Patent Literature 1, the gripping device includes a pair of pads, the distance between which can be changed. Opposed surfaces of the pads maintain a parallel state. The gripping device holds both sides of an object to be gripped using the pads to grip the object to be gripped.
Besides, JP-A-2010-36328 (Patent Literature 2) discloses a robot hand that lifts and grips an object to be gripped. According to Patent Literature 2, thin plate-like claw sections are set at the distal ends of fingers of the robot hand. The robot hand inserts the claw sections between the bottom surface of the object to be gripped and a plane on which the object to be gripped is placed and lifts the object to be gripped. In this method, since the robot hand supports the object to be gripped on the bottom surface, the robot hand can grip even a soft object to be gripped.
The gripping device disclosed in Patent Literature 1 holds a soft object using the side surfaces of the pads. Therefore, when the soft object is deformed by the pressing of the pads, the gripping device cannot grip the soft object. The robot hand disclosed in Patent Literature 2 cannot insert the claw sections when the distance between adjacent objects to be gripped is small. Therefore, there is a demand for a robot hand that can stably grip an object to be gripped even when soft objects to be gripped are located side by side.